I have recently purchased a plane from my childhood. A Sure Flite Baby Birdie became available and I HAD to have one. It's just one of those nostalgic things!

Anyways......I want to convert it to electric. I would like it to be powered in a similar manner to the Cox TD .051 that is was designed around. I wouldn't mind a little less rpm/prop noise as this will be a park flyer.

I would value your opinions on motor/battery for the plane. I will either use a Scorpion or a less expensive Hobby King motor. Please see the pictures for dimensions and weight.

I don't know from HK motors, but I do know what I'd look for in a setup- a 6 to 6.5" prop- probably at least 4" of pitch- and you might be happier with a folder- you'll break fewer props that way. I've used a 6 x 6 folder on a FunX-E which is a slightly larger Baby Phoenix. However, I used a 6" folder in an HOB P-51 too, which is a similar flying airplane. Put at least 250 watts turning the prop and you'll be good to go-should be unlimited vertical and quick.

Hi Doug,
I picked up one of these kits as well. I am planning on using an EFlite six series 2700kv motor in mine with a 6" prop. Not sure whether I will go with a 3 or 2 cell battery yet though. Probably a 3 cell 1300mah or somthing like that.
Blake

Darn, would have liked to have one to complement my .25 sized e-powered Tweety Bird. Right now, I have been flying a new EPO Formosa that is a fine flyer until I can locate a Baby Birdie. Just love the look of that plane!

Umm, no. You've got a pitch speed problem- 43.4 mph is too slow. You want pitch speed to be 2.5x stall speed at a minimum, and for an aerobatic airplane- 3-4x stall speed is closer to it. Assume that the airplane will stall at 18-20 mph.

If you want something less ballistic, I flew an HOB Chipmunk- 216 squares at 21 oz on an 8 x 4 prop swung by an outrunner with 175 watts. Flew quite nicely- good vertical pull, not ballistically fast (which I think is what the Birdie needs but YMMV) so if you can chop some weight out, this might work. I'm assuming you are putting in a rudder-with a larger prop, it's nearly mandatory.

You may also find that mounting outrunners can be a problem, although you can probably get away with a nosering mount. This allows you to delete the firewall and save some weight, plus gives you some access to the motor through the wing saddle area.

FYI- I hate cheapie outrunners- the shafts often bend too easily, they generally don't live up to their specs (I trust Phil's numbers though -aka Dr. Kiwi) so I find that I prefer the old fashioned Mega inrunners. Axi's are decent though. I'm assuming that the airplane is worth enough to you to buy it some decent hardware.

Good assumption. A square prop, i.e. 7 x 7 is not going to work well if you're looking for vertical pull at relatively slow speeds. These props tend to stall out- also they can draw more in the air than on the ground. Plus they're expensive and hard to find. The 8 x 6 is a better bet, but I don't see how you get to a 70 mph pitch speed. The motor rpm is going to drop with the additional load- maybe to 10k rpm- which gets you to 60 mph.

As a general rule- I've been underwhelmed with small, Chinese outrunners. They seem to be much happier running at much less than ratings. Also note that the quality is very inconsistent- there's no guarantee that the motor that Dr. Kiwi tested will actually work that way in your hands. A 70 gram motor seems like a better bet to me to handle the loads you're asking- and I still think you're going to have to worry about bending prop shafts all the time.

In terms of folders- I call Kirk at New Creations- www.newcreations-rc.com IIRC. He's not cheap, but he knows his stuff.

In terms of battery- I'd look at 3s and 1250-1500 mAH-this will give you 4-5 minutes at full bore, or 8 minutes or so of more relaxed flying.